


Synesthesia

by there_must_be_a_lock



Category: Supernatural
Genre: Angel Grace-Induced Drug Trips, Angelic Grace (Supernatural), Dean's Inner Angry Rainbow, M/M, Samstiel? - Freeform, Sastiel - Freeform, Synesthesia
Language: English
Status: Completed
Published: 2020-04-23
Updated: 2020-04-23
Packaged: 2021-03-01 19:22:17
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 751
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23812249
Author URL: https://archiveofourown.org/users/there_must_be_a_lock/pseuds/there_must_be_a_lock
Summary: When Cas warned him there might be side effects, this was not what Sam had in mind.
Relationships: Castiel/Sam Winchester
Comments: 4
Kudos: 72





	Synesthesia

**Author's Note:**

> Inspired by the song "Synesthesia" by Andrew McMahon.

When Cas warned him there might be side effects, this was not what Sam had in mind. 

He’s in the library when it starts. He’s reading, and he’s comfortable, and then he hears the familiar rumble of angry voices; he’s been hearing it for years, and he’d know those voices anywhere. This time, though, it triggers a ripple of strange, ugly distortion across his vision. It’s like the letters on the page are giving off a shimmer that reminds him of the mirage-like waves that come off pavement in the summer, but… not. 

Sam shakes his head and it’s gone. Usually he wouldn’t want to interrupt Dean and Cas when they’re like this, but the voices have dropped, too low for him to hear any more, and his skin is still crawling. Maybe he’s getting sick, but more likely it’s some residual fuckery from that nasty spell they broke last week, and Sam’s learned his lesson about ignoring those signs. 

They’re in the kitchen. Sam sees Dean’s face first, that mulish expression that only ever means trouble, but then Dean starts to talk. 

“Cas -” 

That’s all Sam catches; he’s dimly aware of the sound of Dean’s voice, rising and falling, but the words are a simmering swirl of burnt orange and deep maroon, with the occasional flare of bright, hot red on the sharp bitten-off edges of the syllables. 

Dean’s voice fades. There’s nothing but cold grey left; the two of them are staring each other down, each with a set jaw and crossed arms. It clenches like ice around Sam’s ribcage, the silence between them. 

“Sammy?” Dean barks, and Sam’s stomach dips and soars. Cas whirls around, and Sam is hypnotized by the bright blue in his eyes, wide and concerned in a way that makes Sam feel like he’s being lit up from the inside. There’s a floodlight in his chest. 

“Something weird is happening,” Sam says slowly. “My vision, things are sort of… off. All mixed up.” 

“I told you those were the wrong kind of mushrooms for that potion,” Dean grumbles. His voice is flat but Sam sees it as luminous red like blood through thin veins, pounding, panicky, synapses firing in every direction in strobing flashes, dread creeping up black and thick like tar - 

“Get out of here, Dean,” Cas says calmly. “You’re making it worse.” 

Spikes of metallic fury dance behind his eyelids. Sam can’t make out the whispered conversation they’re having over his head. At some point, he realizes, he sat down on the floor. 

Footsteps recede. 

“It’s okay, Sam,” Cas says. His voice is syrupy gold like honey as he kneels next to Sam. “Side effects, remember?” 

Sam looks at him. It’s an effort to focus, but when he meets Cas’s eyes, Cas smiles. Sam sees a shower of sparks like the last fizzle of a firework. 

“Side effects are usually headaches and nausea, not a surprise acid trip,” Sam manages. The words come out lemony-yellow. 

“You’re seeing some of what angels see,” Cas says matter-of-factly. “You’re getting information from eight dimensions, but your human brain can’t quite process it; the emotion, the truth behind words, gets translated as color.” 

“Jesus fucking Christ,” Sam sighs. Nothing unusual about that, just another fucking Monday evening, right? Cas laughs like he said it out loud, and Sam hears it as a flutter of spring green like a new leaf. 

“I remember it being quite… disorienting,” Cas says wryly. “Your brother, for example. Don’t let the words fool you; there’s a very angry rainbow happening in his head most of the time.” 

Sam grins as the mental image sinks in. “Yeah, that sounds about right.” 

“It’ll pass. Probably.” 

Sam raises an eyebrow at him. Cas extends a hand to help him to his feet. 

When their palms touch, everything blurs and falls away. There are stars under their feet, entire galaxies spinning out around them, dancing spirals of kaleidoscopic green and gold melting into whorls of brilliant blue. There’s an entire universe where their skin comes together. 

Sam shakes his head, pulling himself back down to Earth, drawing himself in until he’s only seeing in the usual three dimensions. He stares dumbly at their joined hands, Cas’s fingers still wrapped around his palm. 

“I was wondering whether you’d notice,” Cas says hoarsely. He’s smiling this sweet, soft smile. 

“Huh,” Sam breathes. He blinks, and looks from Cas’s smile, down to their hands, and back up again. 

Even in three dimensions, he probably should’ve seen that coming.


End file.
